Recently, the synthesis of liquid crystalline polymers has attracted an increasing interest among various macromolecular compounds, because of their versatile applications, such as liquid crystal display (LCD) devices, optical filtering lens, reflection lens, linear optical polarizing lens (Displ. Technol., 1, 81 (1985)), and stationary phase materials used in high performance chromatography (J. Org. Chem., 49, 4947 (1984)). In addition, researchers have focused on their use as an optical memory material in the fabrication of erasable optical discs, for examples articles published in Mol. Cryst. Liq. Letters., 102, 78 (1984); Mol Cryst. Liq. Cryst., 102, 78(1984).
The potential applications of ferroelectric liquid crystals in fast-switching, high resolution electrooptical devices is well documented. [Clark, N. A. and Lagerwall, S. T. appl. Phys. Lett. 1980, 36,899; Lagerwall, S. T. and Dahl, I. Mol. Crys. Liq. Crys. 1984, 114, 151; Lagerwall, S. T., et al. Mol. Cryst. 1987, 152,503]
A number of ferroelectric liquid crystalline side-chain polymers have been prepared during the past few years. Among them there are liquid crystalline polymers having a backbone based on acrylates or acrylate derivatives [V. P. Shibaev, et al. Polymer Bulletin, 12, 299 (1984); J. C. Dubois, et al. Mol. Cryst. Liq. Cryst., 1986, Vol. 137, pp. 349-364; S. Esselin, et al. Mol. Cryst. Liq. Cryst., 1988, Vol. 155, pp. 371-387; S. Bualek, et al. Mol. Cryst. Liq Cryst., 1988, Vol. 155, pp. 47-56; S. Uchida, et al. Mol. Cryst. Liq. Cryst., 1988, Vol. 155, pp. 93-102; K. Shiraishi et al., Makromol. Chem., 190, 2235-2243 (1989); V. Percec, et al. Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 27, 2367-2384 (1989); S. Esselin, et al. Liquid Crystal, 1987, Vol. 2, No. 4, 505-518; B. Messner, et al. Makromol. Chem. 192, 2383-2390 (1991); E. C. Bolton, et al. Liquid Crystal, 1992, Vol. 12, No. 2,305-318; J. Bomelburg, et al. Makromol. Chem., Rapid Commun. 12, 483-488 (1991); G. Scherowsky, et al. Liquid Crystal, 1991, Vol. 10, No. 6, 809-819], liquid crystalline polymers having a backbone of polylaurates [J. M. Guglieminetti, et al. Polymer Bulletin 16, 411-418 (1986)], liquid crystalline polymers having a backbone based on diazo-compounds or derivatives thereof [R. Zentel, et al. Liq. Cryst., 1987, 2(1), 83-89; S. Bualek, et al. Makromol. Chem., 189, 797-804(1988); H. Kapitza, et al. Makromol. Chem., 189, 1793-1807 (1988); R. Zentel Makromol. Chem., 190, 2869-2884 (1989); H. Kapitza, et al. Makromol. Chem., 192, 1859-1872 ( 1991 ); S. U. Vallerien, et al. Makromol. Chem., Rapid Commun., 10, 333-338 (1989)], liquid crystalline polymers having a backbone of polytartrates [S. Ujiie, et al. Polymer. Journal, Vol. 23, No. 12, pp. 1483-1488 (1991 )], and liquid crystalline polymers having a backbone of polysuccinates [K. Fujishiro, et al. Liquid Crystals, 1992, Vol. 12, No. 4, 561-573]. The above-mentioned liquid crystalline polymers do not have a segment of polysiloxane in the backbones thereof.
B. Hahn, et al. in their articles, Mol. Cryst. Liq. Cryst. Inc. Nonlin. Opt., 1988, Vol. 157, pp. 125-150; and Macromolecules, Vol. 20, No. 12, 1987, disclose liquid crystalline polymers having a backbone of polysiloxane. The mesogenic groups of these liquid crystalline polysiloxanes contain 1,3-dioxanyl. C. Destrade, et al. in their article, Liquid Crystals, 1991, Vol. 10, No. 4, pp. 457-493, disclose liquid crystalline polysiloxanes containing .alpha.-chloroalkyl carboxylic acid or aromatic ester of alkyl carboxylic acid mesogenic groups. The present invention is directed to liquid crystalline polysiloxanes containing mesogenic groups of alkyl ester or chloroalkyl ester of aromatic carboxylic acid.
An object of the present invention is to provide novel liquid crystalline polymers.
Another object of the present invention is to provide liquid crystalline polysiloxanes.
Still another object of the present invention is to provide mesogenic monomers for graft polymerizing onto a polysiloxane backbone.